A Century-long Record of Trace Gases in the Northern Hemisphere from the NEEM Ice Core Drilling Project in Greenland
Lead Research Organisation:
University of East Anglia
Department Name: Environmental Sciences
Abstract
An international effort is underway to drill a new ice core in Greenland: the North Greenland Eemian Ice Drilling project (NEEM). This presents an exciting and rare opportunity to obtain 'firn' air and ice cores from a Northern Hemispheric (NH) location. 'Firn air' is air trapped in the porous snow overlying solid ice. This air can be pumped out with a special drilling and pumping arrangement. As one moves deeper in to the snow, the older the air is: eventually representing the composition of air in the NH in the first half of the 20th century. Below the firn, even older air is trapped in individual bubbles in solid ice. We will also extract this air and analyse it, but the measurement is much more difficult and not as many chemicals can be analysed as in the firn. We nevertheless should be able to study the rise of numerous gaseous pollutants (carbon monoxide (CO) and its isotopic composition, hydrocarbons, halocarbons, organic nitrates, etc.) over the last century or more. Deep drilling will begin in the summer of 2008, with a second borehole drilled at that time to extract firn air. Large firn air volumes will be retrieved to enable an extensive suite of trace gases to be measured, and also to permit comprehensive analysis of the isotopes ratios of CO (delta13C, delta18O, and Delta17O). Measurements will concentrate on trace gases with anthropogenic sources, for which we expect to observe significant increases over the last century. We will further concentrate on gases that are relatively short-lived in the atmosphere (lifetimes of weeks to a few years), since prior Antarctic studies have only partly / or not at all - delivered trends of such gases which are emitted largely in the NH. The target gases include those of importance to stratospheric ozone, and those which are precursors of tropospheric ozone, or are proxies of other species (e.g. alkyl nitrates as proxies of reactive nitrogen, NOx: an important driver of global-scale chemistry). The trend and stable isotopic composition of CO will be determined to probe both the past sources of CO (e.g. biomass burning versus methane oxidation) from measurement of delta13C(CO), and past levels of hydroxyl radical (OH) by studying delta18O(CO) and Delta17O(CO). Hydroxyl radical is a crucial component of atmospheric chemistry: often referred to as the 'detergent' of the atmosphere. There is presently little consensus on whether OH has changed over the last hundred years as a result of increased pollution. Any significant decrease would be a cause for concern for future levels of this important molecule.
Publications
Petrenko V
(2013)
A 60 yr record of atmospheric carbon monoxide reconstructed from Greenland firn air
in Atmospheric Chemistry and Physics
Witrant E
(2012)
A new multi-gas constrained model of trace gas non-homogeneous transport in firn: evaluation and behaviour at eleven polar sites
in Atmospheric Chemistry and Physics
Vollmer M
(2015)
Abrupt reversal in emissions and atmospheric abundance of HCFC-133a (CF 3 CH 2 Cl) HCFC-133A REVERSAL
in Geophysical Research Letters
Laube J
(2010)
Accelerating growth of HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane) in the atmosphere
in Atmospheric Chemistry and Physics
Trudinger C
(2016)
Atmospheric abundance and global emissions of perfluorocarbons CF<sub>4</sub>, C<sub>2</sub>F<sub>6</sub> and C<sub>3</sub>F<sub>8</sub> since 1800 inferred from ice core, firn, air archive and in situ measurements
in Atmospheric Chemistry and Physics
Kloss C
(2014)
Atmospheric Abundances, Trends and Emissions of CFC-216ba, CFC-216ca and HCFC-225ca
in Atmosphere
Sapart C
(2013)
Can the carbon isotopic composition of methane be reconstructed from multi-site firn air measurements?
in Atmospheric Chemistry and Physics
Newland M
(2017)
Changes to the chemical state of the Northern Hemisphere atmosphere during the second half of the twentieth century
in Atmospheric Chemistry and Physics
Allin S
(2015)
Chlorine isotope composition in chlorofluorocarbons CFC-11, CFC-12 and CFC-113 in firn, stratospheric and tropospheric air
in Atmospheric Chemistry and Physics
Prokopiou M
(2017)
Constraining N<sub>2</sub>O emissions since 1940 using firn air isotope measurements in both hemispheres
in Atmospheric Chemistry and Physics
Buizert C
(2014)
Corrigendum to ``Gas transport in firn: multiple-tracer characterisation and model intercomparison for NEEM, Northern Greenland'' published in Atmos. Chem. Phys., 12, 4259--4277, 2012
in Atmospheric Chemistry and Physics
Laube J
(2012)
Distributions, long term trends and emissions of four perfluorocarbons in remote parts of the atmosphere and firn air
in Atmospheric Chemistry and Physics
NEEM Community Members
(2013)
Eemian interglacial reconstructed from a Greenland folded ice core.
in Nature
Sturges W
(2012)
Emissions halted of the potent greenhouse gas SF<sub>5</sub>CF<sub>3</sub>
in Atmospheric Chemistry and Physics
Worton D
(2012)
Evidence from firn air for recent decreases in non-methane hydrocarbons and a 20th century increase in nitrogen oxides in the northern hemisphere
in Atmospheric Environment
Zuiderweg A
(2013)
Extreme <sup>13</sup>C depletion of CCl<sub>2</sub>F<sub>2</sub> in firn air samples from NEEM, Greenland
in Atmospheric Chemistry and Physics
Buizert C
(2012)
Gas transport in firn: multiple-tracer characterisation and model intercomparison for NEEM, Northern Greenland
in Atmospheric Chemistry and Physics
Martinerie P
(2009)
Long-lived halocarbon trends and budgets from atmospheric chemistry modelling constrained with measurements in polar firn
in Atmospheric Chemistry and Physics
Oram D
(2012)
Long-term tropospheric trend of octafluorocyclobutane (c-C<sub>4</sub>F<sub>8</sub> or PFC-318)
in Atmospheric Chemistry and Physics
Rubino M
(2016)
Low atmospheric CO2 levels during the Little Ice Age due to cooling-induced terrestrial uptake
in Nature Geoscience
Laube J
(2014)
Newly detected ozone-depleting substances in the atmosphere
in Nature Geoscience
Helmig D
(2014)
Reconstruction of Northern Hemisphere 1950-2010 atmospheric non-methane hydrocarbons
in Atmospheric Chemistry and Physics
Newland M
(2013)
Southern hemispheric halon trends and global halon emissions, 1978-2011
in Atmospheric Chemistry and Physics
Zuiderweg A
(2012)
Stable carbon isotope fractionation in the UV photolysis of CFC-11 and CFC-12
in Atmospheric Chemistry and Physics
Laube J
(2016)
Tropospheric observations of CFC-114 and CFC-114a with a focus on long-term trends and emissions
in Atmospheric Chemistry and Physics
Description | Growth of multiple climate changing and ozone depleting gases during the 20th Century. The occurrence of a number of atmospherically-important gases previously unreported or unrecogised in the global atmosphere The likely cause for the known decline in CO2 during the Little Ice Age as being due to the decrease in respiration being greater than the decline in global gross primary productivity |
Exploitation Route | Global Carbon Project, IPCC, UNEP/WMO Scienttific Assessment of Ozone Depletion |
Sectors | Environment |
Description | See "Influence on Policy" section. Work from this project has been cited in the "Assessment for Decision Makers" of the 2014 Scientific Assessment of Ozone Depletion. This is the document that provides the underpinning evidence base for policy decisions of the Montreal Protocol on Substances that Deplete the Ozone Layer (and its subsequent amendments), and national policies. |
First Year Of Impact | 2014 |
Sector | Environment |
Impact Types | Policy & public services |
Description | Citations in the World Meteorological Organisation/United Nations Environment Programme "Assessment for Decision-Makers" of the Scientific Assessment of Ozone Depletion: 2014 |
Geographic Reach | Multiple continents/international |
Policy Influence Type | Citation in systematic reviews |
Description | Ernst Frohlich Fellowship 2013 |
Amount | $9,600 (AUD) |
Organisation | Commonwealth Scientific and Industrial Research Organisation |
Sector | Public |
Country | Australia |
Start | 02/2013 |
End | 05/2013 |